(CNN)Muhammad Ali, known as "The Louisville Lip" as he began his ascension to boxing greatness, will be celebrated in his Kentucky hometown with ceremonies on Thursday and Friday, a family spokesman said.

A public memorial is scheduled for Friday at 2 p.m. ET at the Yum Center, a basketball arena in the city where Ali grew up and began his amateur career as a 12-year-old. Information on tickets will be released later. The Yum Center has just more than 22,000 seats.

The service will be streamed live on the website for the Muhammad Ali Center.

Spokesman Bob Gunnell said former President Bill Clinton, longtime sportscaster Bryant Gumbel and comedian and close Ali friend Billy Crystal will be among those delivering eulogies.

The immediate family will have a private gathering Thursday. They released a statement Saturday afternoon.

Read More

"Muhammad Ali was truly the people's champion and the celebration will reflect his devotion to people of all races, religions and backgrounds. Muhammad's extraordinary boxing career only encompassed half of his life. The other half was committed to sharing a message of peace and inclusion with the world. Following his wishes, his funeral will reflect those principles, and be a celebration open to everyone."

Ali's daughter Hana Ali said his children surrounded Ali in his final moments, holding his hands, hugging and kissing him and chanting Islamic prayer. She wrote that some whispered in his ear, "You can go now. We will be okay. We love you. Thank you. You can go back to God now."

After Ali's organs failed, his daughter wrote in the tweet, his heart continued to beat for another 30 minutes: "A true testament to the strength of his Spirit and Will!"

"She said, 'You might want to come out,' which I decided to do," he said.

Tributes from around the world

While touching tributes to Ali were pouring in from world leaders, fellow athletes and just regular folk, the boxing great had already addressed how he wanted the world to think about him after his death.

In his book "The Soul of a Butterfly: Reflections on Life's Journey," Ali said he wanted to be remembered as "a man who won the heavyweight title three times, who was humorous, and who treated everyone right. As a man who never looked down on those who looked up to him, and who helped as many people as he could. As a man who stood up for his beliefs no matter what. As a man who tried to unite all humankind through faith and love."

He added, " And if all that's too much, then I guess I'd settle for being remembered only as a great boxer who became a leader and a champion of his people, And I wouldn't even mind if folks forgot how pretty I was."

President Barack Obama said he and first lady Michelle Obama mourn Ali's passing.

"But we're also grateful to God for how fortunate we are to have known him, if just for a while; for how fortunate we all are that The Greatest chose to grace our time," the Obamas said in a statement.

His hometown pauses to reflect

Louisville Mayor Greg Fischer, at a ceremony honoring Ali on Saturday, said the boxer "lived a life so big and bold, it's hard to believe that any one man could do everything he did, could be all the things that he became in the course of just one lifetime."

Fischer added, "Muhammad Ali belongs to the world, but he only has one hometown. The 'Louisville Lip' spoke to everyone, but we heard him in a way no one else could -- as our brother, our uncle, and our inspiration."

People started lining up at 2 a.m. Saturday to see his childhood home, which opened as a museum in early May. Memorials piled up on the front steps and guests paid their respects inside to Ali's brother, Rahaman Ali.

In an interview with CNN, Rahaman Ali said he was very sad because "I won't see my brother in the flesh anymore. It's traumatic, I can't see him anymore. Consolation is that I'll see him in heaven."

Rahaman Ali said his last words to his brother, in a phone conversation, were: "'I will see you tomorrow, Champ. Take care of yourself.'"

Photos:Boxing legend Muhammad Ali

Photos:Boxing legend Muhammad Ali

Since winning a gold medal in the 1960 Olympics, Muhammad Ali has never been far from the public eye. Take a look at the life and career of Ali, the three-time heavyweight boxing champion who called himself "The Greatest."

Hide Caption

1 of 52

Photos:Boxing legend Muhammad Ali

Ali, then known as Cassius Clay, poses in his hometown of Louisville, Kentucky, prior to his amateur boxing debut in 1954. He was 12 years old and 85 pounds. As an amateur, he won 100 out of 108 fights.

Hide Caption

2 of 52

Photos:Boxing legend Muhammad Ali

Ali rose to prominence at the 1960 Olympic Games in Rome, where he claimed a gold medal in the light-heavyweight division.

Hide Caption

3 of 52

Photos:Boxing legend Muhammad Ali

Ali boldly predicted it would take him five rounds to knock out British boxer Henry Cooper ahead of their bout in London in 1963. The fight was stopped in the fifth round as Cooper was bleeding heavily from a cut around his eye.

Hide Caption

4 of 52

Photos:Boxing legend Muhammad Ali

Patrick Power, 6, takes on Ali in the ring in 1963. Patrick was taking boxing lessons after getting bullied.

Hide Caption

5 of 52

Photos:Boxing legend Muhammad Ali

Ali poses for a picture with The Beatles in Miami, during the run-up to his heavyweight title fight against Sonny Liston in 1964.

Hide Caption

6 of 52

Photos:Boxing legend Muhammad Ali

Ali celebrates after defeating Liston in Miami on February 25, 1964. Upon becoming world heavyweight champion for the first time, Ali proclaimed, "I am the greatest!"

Hide Caption

7 of 52

Photos:Boxing legend Muhammad Ali

Ali relaxes after his win over Liston in 1964. At 22, he became the youngest boxer to take the heavyweight title from a reigning champion.

Hide Caption

8 of 52

Photos:Boxing legend Muhammad Ali

Civil rights activist Malcolm X, left, takes a picture of a tuxedo-clad Ali surrounded by jubilant fans in March 1964. Shortly after the Liston fight, Ali announced that he had joined the Nation of Islam and changed his name from Cassius Clay.

Hide Caption

9 of 52

Photos:Boxing legend Muhammad Ali

Known for being as quick with his mouth as he was with his hands, Ali often taunted his opponents. He famously said he could "float like a butterfly, sting like a bee."

Hide Caption

10 of 52

Photos:Boxing legend Muhammad Ali

Ali prepares to defend his heavyweight title in 1965.

Hide Caption

11 of 52

Photos:Boxing legend Muhammad Ali

Ali stands over Liston during their rematch in Lewiston, Maine, on May 25, 1965.

Hide Caption

12 of 52

Photos:Boxing legend Muhammad Ali

Ali eats at a restaurant in 1965.

Hide Caption

13 of 52

Photos:Boxing legend Muhammad Ali

The referee pushes Ali to a neutral corner as Floyd Patterson slumps to the canvas in November 1965. The fight was stopped at the end of the 12th round and Ali was declared the winner.

Hide Caption

14 of 52

Photos:Boxing legend Muhammad Ali

Ali signs an autograph for a fan in 1966.

Hide Caption

15 of 52

Photos:Boxing legend Muhammad Ali

Ali visits a children's home in London in May 1966.

Hide Caption

16 of 52

Photos:Boxing legend Muhammad Ali

Ali trains for his second fight against British champion Henry Cooper in May 1966.

Hide Caption

17 of 52

Photos:Boxing legend Muhammad Ali

British talk-show host Eamonn Andrews shares a laugh with Ali in May 1966.

Hide Caption

18 of 52

Photos:Boxing legend Muhammad Ali

Ali lands a right to the head of Brian London during their bout in London on August 6, 1966. Ali won by a knockout in the third round.

Hide Caption

19 of 52

Photos:Boxing legend Muhammad Ali

Ali looks in his hotel-room mirror in February 1967.

Hide Caption

20 of 52

Photos:Boxing legend Muhammad Ali

The referee counts as Ali looks down at Zora Folley during a championship fight in New York on March 23, 1967. Ali won by a knockout in the seventh round.

Hide Caption

21 of 52

Photos:Boxing legend Muhammad Ali

As a conscientious objector to the Vietnam War, Ali refused induction into the U.S. Army in April 1967. Here, top athletes from various sports gather to support Ali as he gives his reasons for rejecting the draft. Seated in the front row, from left to right, are Bill Russell, Ali, Jim Brown and Kareem Abdul-Jabbar.

Hide Caption

22 of 52

Photos:Boxing legend Muhammad Ali

Ali walks through the streets of New York with members of the Black Panther Party in September 1970. Ali was sentenced to five years in prison for his refusal to enter the draft, and he was also stripped of his boxing title. The U.S. Supreme Court overturned Ali's conviction in 1971, but by that time Ali had already become a figurehead of resistance and a hero to many. Related: Photographer fondly recalls his three days with Ali

Hide Caption

23 of 52

Photos:Boxing legend Muhammad Ali

On November 2, 1970, Ali returned to the ring for his first professional fight in three years. He defeated Jerry Quarry in the third round.

Hide Caption

24 of 52

Photos:Boxing legend Muhammad Ali

Known as the "Fight of the Century," Ali and Joe Frazier split a $5 million purse to fight for Frazier's title on March 8, 1971, in New York. Frazier won by unanimous decision, handing Ali his first professional loss.

Hide Caption

25 of 52

Photos:Boxing legend Muhammad Ali

Ali toys with the finely combed hair of television sports commentator Howard Cosell before the start of the Olympic boxing trials in August 1972.

Hide Caption

26 of 52

Photos:Boxing legend Muhammad Ali

Ali and Frazier appear on "The Dick Cavett Show" in January 1974. The two got into a brawl in ABC's New York studio and were fined $5,000 each.

Hide Caption

27 of 52

Photos:Boxing legend Muhammad Ali

Ali passes a cheering crowd in Kinshasa, Zaire (now the Democratic Republic of Congo), on September 28, 1974. Ali was in the country to fight George Foreman, who had recently defeated Frazier to win the title.

Hide Caption

28 of 52

Photos:Boxing legend Muhammad Ali

Ali and Foreman fight October 30, 1974, in what was billed as "The Rumble in the Jungle." Ali, a huge underdog, knocked out Foreman in the eighth round to regain the title that was stripped from him in 1967.

Hide Caption

29 of 52

Photos:Boxing legend Muhammad Ali

Ali addresses a Nation of Islam meeting in London in December 1974. The following year, Ali left the Nation and embraced a more mainstream Islamic faith.

Hide Caption

30 of 52

Photos:Boxing legend Muhammad Ali

Ali offers advice to future opponent Richard Dunn in March 1976. Ali defeated Dunn in the fifth round two months later. It was his last knockout win.

Hide Caption

31 of 52

Photos:Boxing legend Muhammad Ali

Ali and his third wife, Veronica, second from right, visit the Kremlin in Moscow in June 1978. The two were married from 1977 to 1986. Ali was married four times.

Hide Caption

32 of 52

Photos:Boxing legend Muhammad Ali

Ali takes his daily run along a Pennsylvania country road, shrouded in early morning fog, in 1978.

Hide Caption

33 of 52

Photos:Boxing legend Muhammad Ali

Ali takes a hit from Leon Spinks during their title fight in New Orleans on September 15, 1978. Ali won by unanimous decision, regaining the title he lost to Spinks earlier that year.

Hide Caption

34 of 52

Photos:Boxing legend Muhammad Ali

Ali sits with his daughters Laila and Hana at the Grosvenor House in London in December 1978. He briefly retired from professional boxing the following year.

Hide Caption

35 of 52

Photos:Boxing legend Muhammad Ali

Ali came out of retirement on October 2, 1980, for a title fight with Larry Holmes and a guaranteed purse of $8 million. Holmes won easily, beating up Ali until the fight was stopped after the 10th round.

Hide Caption

36 of 52

Photos:Boxing legend Muhammad Ali

Ali and Trevor Berbick weigh in for their fight in the Bahamas in December 1981. Berbick won by unanimous decision. It was Ali's last professional fight.

Hide Caption

37 of 52

Photos:Boxing legend Muhammad Ali

Ali prays at a mosque in Cairo in October 1986. Two years prior, he revealed that he had Parkinson's syndrome, a disorder of the central nervous system.

Hide Caption

38 of 52

Photos:Boxing legend Muhammad Ali

In 1990, Ali met with Iraqi President Saddam Hussein to negotiate the release of 15 American hostages in Iraq and Kuwait. Here, Ali leaves Iraq with the hostages on December 2, 1990.

Hide Caption

39 of 52

Photos:Boxing legend Muhammad Ali

Ali lights the Olympic torch at the 1996 Summer Olympics in Atlanta.

Hide Caption

40 of 52

Photos:Boxing legend Muhammad Ali

Juan Antonio Samaranch, president of the International Olympic Committee, gives Ali a replacement gold medal in 1996. Ali had thrown his 1960 gold medal into the Ohio River after he was criticized for not fighting in Vietnam.

Hide Caption

41 of 52

Photos:Boxing legend Muhammad Ali

Ali and his fourth wife, Lonnie, unveil his special-edition Wheaties box in February 1999. The box marked the cereal's 75th anniversary, and it was the first time a boxer appeared on the cover.

Hide Caption

42 of 52

Photos:Boxing legend Muhammad Ali

Actor Arnold Schwarzenegger raises Ali's hand during the Celebrity Fight Night charity event in Phoenix in March 2002. Schwarzenegger was presented with the Muhammad Ali Humanitarian Award for his work with the Muhammad Ali Parkinson Research Foundation, the Inner-City Games Foundation and the Special Olympics. The award was presented by former CNN host Larry King, left.

Hide Caption

43 of 52

Photos:Boxing legend Muhammad Ali

Ali arrives in Kabul, Afghanistan, in November 2002 for a three-day goodwill mission as a special guest of the United Nations. He was appointed as a U.N. Messenger of Peace in 2000.

Hide Caption

44 of 52

Photos:Boxing legend Muhammad Ali

U.S. President George W. Bush presents Ali with the Presidential Medal of Freedom, the nation's highest civilian honor, on November 9, 2005.

Hide Caption

45 of 52

Photos:Boxing legend Muhammad Ali

Members of the media watch a video of Ali before the grand opening of the Muhammad Ali Center in Louisville, Kentucky, in November 2005.

Hide Caption

46 of 52

Photos:Boxing legend Muhammad Ali

Ali's wife, Lonnie, watches as actress Alfre Woodard presents him with the President's Award during the 2009 NAACP Image Awards in Los Angeles.

Hide Caption

47 of 52

Photos:Boxing legend Muhammad Ali

On May 24, 2011, Ali appears at the National Press Club in Washington to publicly appeal to Iranian officials for the release of captive hikers Shane Bauer and Josh Fattal. The hikers were released in September 2011, more than two years after their detention.

Hide Caption

48 of 52

Photos:Boxing legend Muhammad Ali

Ali poses during a photo shoot outside his home in Paradise Valley, Arizona, in January 2012.

Hide Caption

49 of 52

Photos:Boxing legend Muhammad Ali

Ali poses for a picture with, from left, Greg Fischer, Len Amato, daughter Laila Ali and Donald Lassere during the U.S. premiere of the HBO film "Muhammad Ali's Greatest Fight" in October 2013.

Hide Caption

50 of 52

Photos:Boxing legend Muhammad Ali

A boxing robe worn by Ali, which belonged to the late country singer Waylon Jennings, went up for auction in 2014.

Hide Caption

51 of 52

Photos:Boxing legend Muhammad Ali

Ali is seen with singer Carrie Underwood at a charity event in Phoenix in April.

Hide Caption

52 of 52

Don King, the boxing promoter who was every bit as brash as Ali, told CNN that in his mind Ali will never die.

"His spirit will go on forever," he said. "He's just a great human being, a champion of the people, the greatest of all time."

Even as the former champ battled Parkinson's disease for his final 32 years, he had the same love for life and people, King said. Parkinson's, which primarily affects a patient's movement, is a "progressive disorder of the nervous system," according to the Mayo Clinic.

Hours before her famed father passed away, Laila Ali posted a throwback photo of him with her daughter, Sydney, who was born in 2011.

"I love this photo of my father and my daughter Sydney when she was a baby! Thanks for all the love and well wishes. I feel your love and appreciate it!!" Laila Ali, herself a former world champion boxer, wrote.

George Foreman, who Ali defeated in 1974 for the world heavyweight title, wrote on Twitter, "It's been said it was rope a dope Ali beat me with. (N)o (it was) his beauty that beat me. Most beauty I've know(n). loved him."

It's been said it was Rope a dope, Ali beat me with no his beauty that beat me. Most beauty I've know loved him pic.twitter.com/G64WX3eyZC

Champion for Parkinson's families

In recent years, Ali had largely stayed out of the public spotlight. In his last known appearance, he appeared at a Parkinson's fundraiser April 9 in Phoenix, according to the Arizona Republic. A photo posted by the newspaper showed Ali wearing dark sunglasses.

On the website of the Michael J. Fox Foundation, the actor -- who also has Parkinson's -- said: "Muhammad was a true legend -- a champion in the boxing ring, and a champion for millions of Parkinson's families. We looked up to him as an example of grace and courage in the face of great challenges."

Ali was known not only for his athletic prowess but also for his social activism.

He was born in January 1942 as Cassius Clay. He began boxing as an amateur after his bicycle was stolen and a police officer offered to train him. Clay won a gold medal as a light heavyweight at the 1960 Olympics then turned pro, fighting his bout in his hometown.

In 1964 he became heavyweight champion (the youngest ever at the time) with a surprising knockout of Sonny Liston. That year he joined the Nation of Islam and changed his name.

Ali's sparkling career was interrupted for 3½ years in the 1960s when he refused induction into the U.S. Army during the Vietnam War and was convicted of draft evasion. The Supreme Court overturned the conviction.

Ali was prepared to go to prison, King said.

He stood his ground on who he was," King said. "He'd rather go to jail than break what he believed in."

During his boxing hiatus, Ali spoke frequently about racism in America.

"At a time when blacks who spoke up about injustice were labeled uppity and often arrested under one pretext or another, Muhammad willingly sacrificed the best years of his career to stand tall and fight for what he believed was right," Abdul-Jabbar wrote on Facebook. "In doing so, he made all Americans, black and white, stand taller. I may be 7'2" but I never felt taller than when standing in his shadow."

Ali went on to win the heavyweight title twice more before retiring for good in 1981 with a record of 56-5.